Watermarking of paper.



PATENTED MAY 22, 1906.

K. mommy WATBRMARKING OF PAPER.

APPLICATION FILED 00125, 1905.

2 SHEETS'wSHEET lv PATENTED MAY 22,1906.

W, K. TROTMAB'L WATERMARKING OF PAPER.

APPLIGATION FILED OCT.5,1905.

2 SHEETS-SHEET 2 UNITED STATES Parana W ALTER KNOWLES TROTMAN; OF WOOD GREEN, ENGLAND.

' WATERMARKING or PAPER.

Specification of Letters Patent.

Patented er es ieee.

To all whom it ,may concern:

Be it known that I, WALTER KNOWLES TROTMAN, a subject of the King of England, residing at Wood Green, London, England, have invented certain new and useful Improvements in or Relating to the VVaterInarking of Paper, ofv which the following is a specification.

This invention relates to the watermarking i of paper, and is more especially concerned with the rolls, usually the dandy-rolls, used for that purpose.

I will here describe a dandy-roll of my i1nproved construction According to present practice it is customary when a new Watermark has to bemade to provide an entirelynew dandy-roll at considerable expense. By my invention I avoid the necessity for this.

In carrying out my invention I construct the cylindrical portion of the roll and its covering much according to present practice; but instead of making these parts continuous throughout the whole of the roll I make them in sections, some of which are movable. This may be carried out in the following manner: The ordinary practice in making rolls of this description is-to have a hollow shaft or spindle upon which are a series of circular open disks. Upbn these lies the cylindrical outer portion of the roll, constructed usually of lonlgitudinal wires or rods upon which is wound a length of wire with spaces between the convolutions, this circumferential wire'being soldered, sewed, or otherwise secured to the longitudinal rods. This cylindrical backsheet, as it is called, is usually in a single piece, and upon it is placed a wire-gauze sheet forming the outer surface'of the roll, and upon this in the ordinary practice the deviceintended to produce the water-mark is dered or otherwise secured.

In my improved roll both' the backingsheet and the gauze covering are made with certain portions or sections removable. This maybe managed in various ways; but conveniently the previously-mentioned longitu dinal wires are interrupted in theirlength and secured to segmental pieces, preferably of metal and provided with hooked or other suitable slots or other: fastening devices by which they can be secured in place in or upon the cylinder. The gauze covering is removably secured upon the section of the backingit can be withdrawn and an provided with -the necessary sheet, so that other sect-ion the ,whole section is replaced in the roll.

Various means may be adopted for securing the covering 'upon the backing-sheet, a convenient method being to provide one edge of the gauze sheet with a longitudinal stiffener the ends of which fit into suitable slots in the ends of the segment of the backingstrip. The other end may be similarly constructed, preferably to fit into holes which may be advantageously square, or one end of the stiffener is secured by. a spring or other suitable fastening. 1

In the accompai ying drawings, Figure l is an elevation, part1 n section, of one form of dandy-roll enrbodying this invention. Fig.

1 2 is a transverse section on the line 2 2 of Fig.

" 1; and Fig. 3 is an internal perspective view of. a reinovable'section of the roll.

Like letters indicate like parts throughout the drawings.

[ water mark device substituted, after which Upon a hollow shaft A is fixed a series of circular open disks B. To the periphery of. these disks is attached the cylindrical frame of the roll, constructed of longitudinal rods C, upon which is wound a length of wire D, with spaces between the convolutions. This circumferential wire is soldered, sewed, or otherwise secured to the Longitudinal rods f). Upon. this cylindrical bacl -sheet of wire D is placed a wire gauze shegt E, forming the outer surface of the roll.

In order to enable certain portions or sec tions of the roll to be removable, some of the longitudinal rods C are interrupted in their length and terminate at two disks B B, between which a space is left round a part of the circumference of the roll. The section adapted to fill this tudinal bars C, secured to segmental pieces F and carrying the wires or bacl'ing -sheet D, upon which is placed the section of wire-gauze sheet E.

The device intended to produce the Water mark is soldered or otherwise secured to the section of gauze E. The segmental. pieces F are slotted at F to enga e pins 15 projecting from the disks B, by which the removable section'may be guided into its proper posi tion in the roll. t will be understood that the removable sections are so constructed space comprises the longithat they fit the roll exactly as though they actually formed an integral part thereof.

To fasten the removable section in or upon the cylinder, a short rod G is secured between two of the segmental pieces F to act as a E "catch. A rotatable spindle II is supported upon the rod G when the spindle H is turned,

I the end with an arm or handle H arranged spring-catch H.

- larly in Figs. 2 and 3, the gauze covering E is the ends of the section.

. hollow shaft and the perforated disks, relying upon longitudinal rods to give sufficient in bearin s H on the hollow shaft A and eX- tends rig t along inside the roll. This carries a hook H preferably of slightly spiral form, which is arranged to engage the rod G when the removable section is placed in position and to exert an inward radial pressure so that the removable section is firmly held in position. The spindle H may be provided at to be held in the gripping position by a In "the construction illustrated, particuremov'ably secured upon the section of the backing-sheet D as follows: One edge of the gauze sheet E is provided with a longitudinal stiffener J, the ends of which fit into suitable slots F in the segmental pieces F at The other edge of the gauze sheet E is provided with a stiffener K, one end K of which is square and adapted to fit into a square hole F in one end segment F. At the other end of the stiffener K a sliding pin K is arranged to pass through a hole F in the end segment and into a hole or tube K in the stiffener. To remove the wire gauze E from the back-sheet D, the pin K is shifted out of engagement with the holes K and F, the stiffener K is released, and the stiffener J may. then be removed from the slots F I have above described a method of carrying out my invention in conformity as nearly as possible with present practice. Nevertheless I wish it to be understood that I do not restrict myself to employing a separate back ing-sheet and gauze covering for each sei- .on or for the'whole roll, as these may be made or fixed permanently together as a single piece or section. Also I need not necessarily use wiregauze at all, as other materials or things may be substituted for this purpose. Nevertheless usually some form of wire-gauze or equivalent is desirable, and I generally find it referable to make it separate from the backing-sheet.

Although the previously-described open disks arranged upon a hollow shaft may, as stated, he used, I can dispense with both the stability to the roll. In such case if-I have to :emove portions of the longitudinal rods to accommodate my removable sections any desired means of stiffening or strengthening the mngitudinal wi es at those parts, or altogether may be employ l. The invention is equally applicable to the flat frames such as are used in the manufacture of paper by hand.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A dandy-roll the cylindrical portion of which comprises a removable section earrying the watermarking devices for the purpose described.

2. In a dandy-roll the combination with the cylindrical portion of the roll having a space therein of a section of backing-sheet and a covering carrying a watermarking device both arranged to fit into the space for the purpose described.

3. In a dandyroll the combinationwith the cylindrical portion of the roll having a space therein of a section of backing-sheet and a detachable gauze covering carrying a watermarking device both arranged to fit into the spa for the purpose described.

4. In a dandy-r611 the combi ation with the cylindrical portion of the roll f a removable scction and means for secunng such section in place. Y

5. In a dandy-roll the combination with the cylindrical portion of the roll of aremovable section engaging with the roll and a hook rotatably mounted on the roll and arranged to secure the removable section in place.

6. In a dandy-roll the combination with the cylindrical portion of the roll of a removable section, a detachable gauze covering on such section, a watermarking device carried by said covering and stiflcners attached tothe covering and adapted to engage with the section.

7. In a dandy-roll the combination of a cylindrical portion consisting of gauze suppor cd upon a frame formed by disks B longitudinal rods C and backing-sheet D and having a space therein, a removable section consisting of segmental pieces F, bars 0, backing-sheet D and gauze covering E carrying a watermarking device, means for engaging the gauze covering E with the removable section and means for securing said section in place on the cylindrical portion substantially as described.

8. In an apparatus for watermarking paper, the combination with a wireframe having a s )ace therein, of a removable section of the frii me carrying the watermarking device for t1.) purpose described.

In testimony whereof I. havi signed my name to this specification in the presence of two subscribing witnesses.

WAli'lElt KNOWLES 'IROTMAN.

Witnesses:

Amman J. BOULT, .IIARRY B. BRIDGE. 

